1. Field of the Invention
The invention relates to a brush block as well as to a slip ring assembly for transmission of electrical signals by means of sliding contacts between mutually rotatable parts. At least one sliding contact which is made of an electrically conductive material and is also known as the brush, slides on a slideway which is also made of an electrically conductive material. Electric current is transmitted by galvanic contact between the slideways and the contact.
2. Description of Relevant Art
A brush block, in which spring wires are soldered in a printed circuit board, is known for example from DE 201 15 215 U1 or also known from U.S. Pat. No. 4,583,797. The manufacture is relatively simple, whereby a precise positioning of the individual brush wires is hardly possible. Furthermore, the durability is not satisfactory for continuous use, since the solder joints break over time.
In EP 1453155 A2 a slip ring brush is disclosed which is soldered on the top of a printed circuit board. By flowing of solder from the underside of the printed circuit board, it is attempted to obtain a large-area solder joint which then should achieve a sufficient mechanical strength. A disadvantage of this brush block is that, besides the complex manufacturing, only a U-shaped brush assembly can be realized due to the large contact length of the brush wire on the printed circuit board, and in order avoid lateral forces on the solder joint. Thus, two brushes abut at opposite positions of the slideway, which requires much assembly space and allows only two brushes per slideway. DE 101 58 381 B4 discloses a slip ring transmitter, wherein a contact spring is fastened on a printed circuit board by a clamping mechanism. In JP 2010-232139A a generic assembly is disclosed, wherein the brush wires are soldered in through-holes.